Annual Summary Information for Ozone
* Prior to 2008, the 8-hour ozone exceedance day tables reflect the 1997 NAAQS (84 ppb) and from 2008 forward, the tables reflect the 2008 NAAQS (75 ppb). Tables from 2016 forward reflect the 2015 NAAQS (70 ppb).
** EPA's 2004 Implementation Rule revoked the 1-hour NAAQS, effective June 15, 2005, but states are not allowed to backslide from existing 1-hour ozone requirements.
1 Ozone season was expanded in 2017 to include March.
Content last updated on April 10, 2018